This invention relates to the prevention of root damage to underground drain pipes. It is well known in plumbing and home maintainance fields that roots cause considerable damage and inconvenience by damaging and invading underground drainage pipes. Domestic drainage pipes are commonly laid in a below-ground region shared with the roots of trees and shrubs. Pipes, over time, are subjected to tension, compression and sheer forces, due to ground shifting and due to expansion and contraction caused by changes in temperature. Frost and animals may cause damage, and in the case of metal pipes, especially iron pipes, electrophoretic effects lead to rusting, oxidation and decomposition. Pipes can be subjected to chemical attack from inside, such as from chemicals being flushed into a drain, for instance when caustic or acidic chemicals are poured down a drain to dislodge a clog such chemicals may remain behind the clog for a considerable time until the clog is dislodged. Damage to underground pipes increases with age of the pipes, and since the pipes are underground,often goes undetected until there is a serious problem.
Along with water, underground pipes frequently carry away domestic sewage which is high in nitrates, other minerals and organic compounds that stimulate root growth. These growth-stimulating compounds are very attractive to plants. Water, of course, is also needed by plants and as such, plant roots grow towards sources of water. Plant roots sense water and nutrient compounds at very small concentrations in the soil and will grow up a gradient of such compounds towards the source of the compounds. Even a tiny leak from a pipe is often sufficient to attract root growth. Such root growth is not random, but directional, and growing roots will seek out the source of the stimulating compound. Roots will grow towards any leak in a pipe, such as a loose joint or crack, and will grow into this place. The insinuating root grows both axially (lengthwise) and radially (in diameter) and as its girth expands it will cause further damage to the pipe, causing cracks and severe leaks that may eventually necessitate digging up the pipe to effect replacement or repair. Obviously such repair is expensive and inconvenient. Often, rather than breaking the pipe, the effect of root growth will be to block the pipe. This happens when roots invade the lumen of the pipe and, because of the high nutrient concentration, proliferate inside forming a mass of roots that can trap solid matter and quickly block the pipe. This, of course is advantageous to the plant, producing a mass of roots with large root surface area over which nutrients are absorbed, but is bad for the pipes and for the owner who must pay for repairs.
The prior art solutions to these problems have involved mechanical and chemical removal or roots, and when pipes have been damaged, digging up and replacing the pipes. Dealing first with damaged and leaking pipes, the only solution is excavation of the area, cutting back and destruction of the roots, and replacement of the pipes. Excavation is very costly, not least because the location of the damage is frequently not apparent until it has been uncovered, necessitating digging a trench along the path of the pipe until the point of damage has been found. Having found the damage, the roots must be cut back, necessitating further digging. If roots are to be destroyed, they may be poisoned, for instance by the injection of a powerful root poison directly into the root or the application of such a poison to the outside of the root. Such poisons often kill the entire tree or shrub, which is frequently undesirable, especially in the case of larger trees or shrubs, which when dead, require expensive removal and stump extraction.
Turning to the problem of pipes blocked by invading roots, the least expensive and inconvenient solution is often to treat the pipes with a substance that poisons and/or dissolves the roots. These substances, which may be poured down a drain or poured into a toilet, are frequently toxic to humans, other animals and to plants. The substances are usually in liquid form and are flushed into the drain where they contact the roots. Because these treatments require time to work, it is essential that the toilet or bath etc not be used for a certain amount of time, usually several hours. Apart from the inconvenience this causes, such directions are often not followed, making the treatment ineffective and a waste of time and money. This is especially so in the context of an apartment building or shared housing where many units share a common drain pipe; it can be hard to coordinate all tenants not to use the bathroom for several hours. The cost of these problems is well known to all apartment owners and managers.
Chemical treatments are only partially effective and often the root ball inside the pipe cannot be effectively removed by these methods. Roots are made of lignin which is tough and resilient to degradation. Even when dead, the roots may continue to block the pipe. Additional treatments are often administered, causing additional expense and additional pollution by pouring still more toxic substances down the drain, which leach out into the soil and may eventually reach ground-water, rivers and streams and potentially contaminating drinking water. Such additional treatments may be equally ineffective, leaving only one solution, mechanical removal. Certain chemical treatments have been designed to foam inside the pipe, thus filling the entire lumen of the pipe to effect better contact with both the upper surface and the lower surface of the pipe. Such foaming treatments, however, still have all the general disadvantages of chemical treatments, because, to work, they need to be concentrated upon the clogged area for several hours. Toxic treatments may adhere to the sides of drain pipes and so inhibit root growth, but this inhibition will last only until these substances are washed away, not providing effective deterrence of root growth.
Mechanical removal usually requires calling out the "rooter" company which uses a flexible snake which may have knives attached to the end to cut through roots. Cutting the roots removes them, at least partially, but does not prevent renewed root growth which may be very rapid, and it is therefore only a temporary solution. Also, mechanical removal does not repair the damaged pipes, nor does it prevent initial or further root growth into the pipes. All in all, mechanical removal may be a practical solution to an emergency problem of root-blocked pipes, but it is a temporary solution with no preventative qualities, and it is expensive.
There is a need for a treatment that cures the problem of root growth in underground drainage pipes and that prevents and deters root growth into pipes. There is a need for a substance to prevent root growth that is safe to use and is non-poisonous to humans, other animals and plants, and that is easily biodegradable. There is a need for a substance to prevent root growth that will not kill the entire plant from which the roots emanate. There is a need for a treatment that can be applied continuously and effectively, with the minimum of inconvenience. There is a need for such a treatment that is inexpensive. There is a need for such a treatment that can be used without requiring that bathrooms must not be used for the treatment period. There is a need for a hormonal treatment for pipes that prevents root invasion and growth wherein the hormone can be delivered automatically and simply each time a toilet is flushed.